This invention relates to a superoxidized sodium perborate and to a process for its preparation.
Superoxidized sodium perborates (SOPB) are known products. German Offenlegungsschrift No. 28 11 554, discloses an SOPB which contains more than 17% by weight active oxygen and less than 1.4 atoms hydrogen per active oxygen atom. It is prepared by introducing metaborate solution and H.sub.2 O.sub.2 in a molar ratio of 1:&gt;1.2 into a fluidized bed of previously introduced nuclei and evaporating the water contained in the aqueous solution. In this way, products are obtained which are evidently a mixture of different types of adducts of peroxyborate, as expressed by the suggested empirical formula: EQU (NaBO.sub.3.H.sub.2 O.sub.2).sub.x.(NaBO.sub.3.H.sub.2 O).sub.y.(NaBO.sub.3).sub.z
Other SOPB are known from British Pat. No. 798,217 and French Published Application No. 1,590,710. The former are obtained by contact drying by passing solutions of H.sub.2 O.sub.2 and metaborate over a hot surface at 100.degree. to 130.degree. C.; the latter are obtained by precipitation from an organic medium. Both SOPB are evidently adducts of H.sub.2 O.sub.2 to peroxyborate.